Res . Agric . Livest . Fish . Vol . 3 , No . 1 , April 2016 : 203-216 PRESENT STATUS OF NATURALLY OCCURRING SEAWEED FLORA AND THEIR UTILIZATION IN BANGLADESH

Seaweed, Macro-algae, Hypnea, Hydrocolloid, Cox’s Bazar, St. Martin Island A survey was conducted to know the present status of naturally occurring seaweed flora and their utilization in Bangladesh by interviews of scientific officers of MFTS (Marine Fisheries and Technology Station, Bangladesh Fisheries Research Institute, Cox’s Bazar), NGO officials associated with seaweed research project, local seaweed food products manufacturer, seaweed collectors and Mog or Rakhyine tribal community of Cox’s Bazar and St. Martin Island. Lack of knowledge on availability, distribution, seasonal variation, utilization status is causing impediment on utilization (e.g. seaweeds as human food, hydrocolloids, animal feed, fertilizer, cosmetic products, etc.) of available seaweeds naturally occurring in Bangladesh. Seaweeds are available along the whole Bangladeshi coast, mostly in St. Martin Island, Cox’s Bazar and Sundarbans Mangrove forest. Total 193seaweed species including 19 commercially important species, belonging to 94 genera are found. Approximately, 5,000 metric ton of seaweed biomass is available. Due to seasonal variation in water quality parameters, generally seaweeds are available from October to April, but highest abundance occurs from January to March. Seaweed salad and sauce has been utilizing by Mog people as food. About 400 seaweed collectors at St. Martin Island annually harvested 6-9 metric tons of wet seaweeds (Hypnea spp.) for smuggling to Myanmar. Different value added food, functional food and personal care products have prepared by Govt. institution, NGO and in private sector. Considering the economic importance and potentials of seaweeds, for effective and environmentally sustainable utilization, special concern is required by both government and private organizations.


INTRODUCTION
"Seaweed", is a colloquial term for the common name of countless species of microscopic and mostly macroscopic, multicellular algae which do not have root systems or flowers, leaves, stems, fruits and seeds and generally grow and live attached to rock or other hard substrata below the high-water mark or remain drifted in the oceans (Chapman,1973;Santhanam et al., 1990;Okazaki, 1971;Round,1970;McHugh, 2003, National Ocean Service, 2015).Seaweeds are found in the coastal climatic zones throughout the world i.e. from the warm tropics to the icy Polar Regions.Seaweeds have been reported to be used for various purposes by the Romans, Egyptians, Japanese, and Chinese in the ancient time (Drugs.com,2015, National Ocean Service, 2015, Dillehay et al., 2008).The extent and scope of seaweeds utilization in this modern world is increasing (McHugh, 2003).
Utilization of seaweed as human food was once confined only in Japan, China and Republic of Korea but now spread to mass people of North America, South America Europe and Australia (McHugh, 2003, Kılınç et al., 2013).Apart from conventional seaweed food products like Japanese Nori or Purple Laver and Korean Wakame, seaweed food products like burger, juice, sandwich, chocolate, ice-cream, cake, salad, biscuit, chips etc. are producing on commercial basis (Sarkar, 2015).The most remarkable utilization of seaweed is found in phycocolloid or hydrocolloid industry and cosmetic industry, biofuel industry, pharmaceutical industry for the development of drugs for Alzheimers' disease, cancer and gastric ulcer, waste water treatment industry, bioplastic industry (De Roeck-Holtzhauer, 1991;McHugh, 2003;Wargacki et al., 2012;Burtin, 2003, National Ocean Service, 2015; Gade et al., 2013).
The scenario of utilization of seaweed in different economically valuable ways is quite opposite in Bangladesh except utilization by Mog or Rakhyine tribal community and seaweed collectors of St. Martin's Island (Majumder, 2010, Sarkar, 2015).Recently some recent experimental approaches on seaweeds' utilization were reported (DoF, 2014, COAST Trust, 2013).The seacoast of Bangladesh is one of the unreached areas of the world in the field of phycology.There is lack of very fundamental information and statistics regarding seaweeds distribution, total seaweeds and commercially important species available, abundance, seasonal availability, status and approaches for utilization in Bangladesh (Majumder, 2010;Khan, 1990).Without these information and statistics, it would be impossible to figure out feasible seaweed spp.for commercial utilization.Identification of just only one species; Gracilaria sp. from Penang leaded Malaysia toward agar production and utilization through Gracilaria sp.farming (Doty and Fisher, 1987).This study was designed to know the present status of naturally occurring seaweeds flora and its utilization pattern in Bangladesh

MATERIALS AND METHODS
Natural seaweeds in Bangladesh are available from October to April throughout the whole southern coast (Majumder, 2010;Islam 1976Islam , 1998;;Islam and Aziz 1987).Extensive water sampling and collection of seaweed specimen from exposed rock surface during low tide could be conducted to determine the present status of naturally available seaweeds in Bangladesh (Majumder, 2010) which will be very difficult due to large expanse, long time and very hard labor.So, to acquire information on present status of naturally occurring seaweeds a survey work was conducted.

Study area
Although seaweeds are available throughout the southern coast but most of the available seaweed species are found to grow naturally at Cox's Bazar.Great abundance of natural seaweed resource is reported at St. Martins' Island (DoF, 2014).Considering these points, Cox's Bazar and St. Martins Island was identified as the study area for data collection on seaweeds and their utilization (Figure 1).

Identification of target groups for data collection
Scientific officers of MFTS and NGO officials of COAST Trust, Jahanara Islam (renowned entrepreneur of Cox's Bazar, Bangladesh), Mog or Rakhyine tribal community of Cox's Bazar and seaweed collectors of St. Martin's Island were identified as target group.

Data collection approaches
Data mining from previous reports on seaweeds of Bangladesh.PRA tools: questionnaire interviewing, group discussion, cross check interviewing, transect walking were employed for scientific officers of MFTS, NGO officials of COAST Trust and Jahanara Islam.Seaweed collectors were interviewed by a semi-rigid questionnaire.

Distribution of seaweeds
Favorable climatic, environmental conditions and interconnected network of waterways make natural availability of seaweeds throughout whole Sundarbans mangrove forest wherebenthic forms of seaweeds naturally grow in inter-tidal areas on pneumatophores of mangrove tree, other wooden logs and barks of trees.Around 60 seaweed species are found from Sundarbans and amongthose, Boodliopsissun darbanensis, Ulvalactuca and U. intestinalis, Catenellarepen, C. nipae, Gelidium, Polysiphonia, Ceramium, Bostrychia, Compsopogonetc.areavailable.
About 155 seaweed species are found in Cox's Bazar.In Cox's Bazar region, seaweeds are very abundant at Shilkhali/Shaplapur coast, Jaillapara, Shahparirdip area of Teknaf, Nuniarchara,Nazirartek of Bakkhali-Moheshkhali river estuary, MoheshkhaliIsl and and at planted mangrove forest or Parabon region.In Cox's Bazar, natural seaweed beds are found atNuniarchara to Nazirartek areas of Bakkhali River and Moheshkhali Channel estuary and in Moheshkhali Island.Hypnea musciformis and Enteromorpha intestinalis are the main seaweed species of seaweed beds.

Available seaweed species
About 193 seaweed species of 94 genera belonging to only three major divisions i.e.Chlorophyta-green algae, Phaeophyta-brown algae, Rhodophyta-red algae are available in Bangladesh (Table 1).Commercially important seaweed species: Among the available seaweed species, 19 species of 14 genera are considered as economically important (Table 2)

Natural production of seaweeds:
Approximately, 5,000 metric ton seaweed biomass is annually available throughout the whole Bangladeshi coast from October to April.

Approaches for seaweed utilization by private entrepreneur and non-government organization
Several seaweed foods, functional and personal care products have been developed by Jahanara Islam (Figure 3).The post-harvest handling procedure followed by that private entrepreneur is presented at Figure 4.A local NGO named COAST Trust also prepared different value added food and functional food products (Figure 5).

Harvested seaweed
Washing with saltwater

Washing with freshwater
Drying in open air on net under shade of coconut plant for 2 days, mild sun drying can be used Cover the weeds at night to prevent blackening of weeds due to fog Storage of weeds on a platform in a cool, dry, moisture and damp free condition Water quality parameters of the St. Martin's Island, which situated in the extreme South-eastern corner of Bangladesh, appear to be very positive for seasonal abundance (Khan, 1990;Tomascik, 1997;Zafar, 2005;Haque, 2013;COAST Trust, 2013).Rocky substrates, which are crucially required for seaweedhabitat are available around the St. Martin Islandexcept the north coast (FAO/NACA, 1996; Hossain, 2004).Therefore, St. Martin Island is an extraordinary place for natural availability of seaweeds (Figure 06).
Due to less violent wave action in eastern coast for close proximity to Myanmar territorial land mass , less deposit of drifted seaweeds is reported in eastern coast than western coast (Figure 07).Due to the absence of rocky substrates in the northern coast seaweeds are not available there.Therefore, presence of rocky substratum and Geographical position of St. Martin Island causes variation in distribution of seaweeds around St. Martin's Island (Majumder, 2010).

Commercially important seaweeds species
Ten seaweed species were documented as commercially important species by Khan(1990) and Majumder(2010), whereas,DoF (2014) assumed 20 seaweed species can be commercially important.

Natural production of seaweeds
Regular statistics on production of seaweed is yet to be developed.About 1,500 MT seaweed biomass was reported from the St. Martin Island (Sarkar, 1992).

Seasonal variation in seaweeds' availability
In seasonal variation in seaweeds availability are basically due to variation in water quality.Geographical and vertical distribution and growth of seaweed are governed by various factors like water temperature, salinity, pH, dissolved oxygen, water transparency, nutrients etc. (Luning, 1990).Specific water quality parameters are required for growth and propagation of seaweeds (Round, 1970) and that's whyseaweeds can only be found in those season or months of the year where water quality is favorable.Seaweeds in Bangladesh are available in winter, summer and spring seasons.As, the water quality parameters remain in peak in respect of favorable conditions of seaweeds, the highest abundance of seaweeds found from January to March.Similar finding was also reported by FAO/NACA, 1996.Salinity can be considered as an example of physical parameter of water.Heavy rainfall during the monsoon season lowers the salinity of coastal region than the other seasons of year.For growth and propagation 20-34 ppt salinity is required by seaweeds.This range or around this range is available only from October to April.
Abundance of seaweed is also influenced by pollution, disturbance etc.The present day populations of marine algal flora are very different from what they were in 1960s and even 1980s, and this degradation may be ascribed to continuous disturbance of inter-tidal rocks, particularly for construction and household use, is an impediment to growth of marine algae.The dragging of seine nets across the inter-tidal zone adversely affects seaweed settling.Pollution is also an issue: waste entrance to coastal waters may affect marine algae growth (MoEF, 2001; Thompson and Islam, 2010).

Conventional utilization of seaweed
Utilization of seaweed by Mog or Rakhyine tribal community was reported by Majumder, 2010.Kamal, 1994;Zafar, 2005Majumder, 2010 and COAST Trust, 2013 reported about utilization of dried seaweeds by illegal trading to Myanmar from St. Martin's Island.In St. Martin's island, about 100 people, mostly fishermen, children and women, were engaged in collecting seaweeds particularly Hypneaspp manually by hand or using nets like push net during low tide.About 40-80 kg seaweeds can be collected per day per person depending on the abundance.The weeds were dried in the sun on the open sandy beach and it took 3-4 days to dry.Price of seaweeds from seaweed collectors to wholesaler is reported as BDT 80-100, wholesaler to Myanmar trawler as BDT 400-500 and about 200 tons of seaweeds are annually smuggled to Myanmar (Figure 08) (Kamal, 1994;Zafar, 2005Majumder, 2010).Medicinal use of seaweeds was also reported by Majumder,2010.

CONCLUSION
Seaweeds have potential to emerge as an individual export oriented industry in Bangladesh.More comprehensive studies on present status of naturally available seaweeds and their present status of utilization should be conducted and a long-term scheme for utilization of this resources required establishing.

Figure 1 .
Figure 1.Selection of Cox's Bazar and St. Martians Island as study area from red marked Bangladeshi coast where seaweeds are naturally available every year from October to April.

Figure 4 .
Figure 4. Post harvest management flow chart used by Jahanara Islam

Table 1 .
Seaweed species available in Bangladesh

Table 1 .
Seaweed species available in Bangladesh (contd.) Notes: Habit: TH= Thalloid/micro-or macro thailus; F = Filamentous, microscopic; Habit at: E = Epiphyte on other marine macro algae; R = On rocks/entangled with other seaweeds under sea water in the intertidal zone; National Status: VU = Vulnerable